Treatment of precious metalliferous ores.



JOHN COLLINS CLANCY, OF NEW ,YORK, N. Y.,

ASSIGNOR TO GLANCY METALS PROCESS COMPANY, A CORPORATION-OF NEW YORK.

TREATMENT OF PRECIOUS METALLIFEROUS ORES.

N 0 Drawing.

Specification of Letters Patent. Patentd July 25 11 9111, Application filed March 17, 1910. Serial No. 549,958.

I '0 all wiiom it may concern:

Be itknown that I, JOHN CoLLINs Comer, a subject of the King of Great Britain, having declared my intention of becoming a citizen of the United States, at present residing at New York city, borough of lilanhattan, in the county of New York and State of New York. have invented certain new and useful Improvements in the 'lreatment of Precious Metalliterous Ores, of which the following is a specification.

My invention relates to novel methods of treating ores bearing precious metals, which methods are particularly described and pointed out in the following specification and. claims.

l have discovered that when the pulverized ore is converted into a pulp by mixing the said ore with a substantially non-acid solution of a thiocyanatc containing a halogen salt, and electrolyzing this mixture, that the precious metals only will be dissolved to the substantial exclusion of the baser metals, and that the above solution may be used with advantage in conjunction with the ordinary cyanid solution, and that this process may be successfully applied to either rebellious or nonrebellious ore without preliminary roasting even though such ores contain reducing agents or tellurium or both. A

In treating. ores containing among other compounds silver sul-tids, it may not be neces ary to add a halogen salt to the thiocyanate solution as the nascent. oxygen produced by the electric current will act according to the second equation shown herein.'

I give the following examples of my process without, however, limiting myself to the details of each:

Example 1: 2000 pounds of pulverized ore are suspended in a solution of 2 pounds of thiocynate, 2 pounds of caustic soda or caustic lime, 1 pound of potassium iodid in an agitation tank, the mixture being in the proportion of two'p'arts said solution to one part of ore. This mixture of ore and solution is continuously circulated for a period of eight hours through an electrolyzer having a current density of about 50 amperes per square foot of anode surface.

are used per 1 pound of potassium iodid in an agitation.

tank, the mixture being in the proportion of two parts said solution to one part of ore. This mixture of ore and solution is continuously circulated for aperiod of eight hours through an clcctrolyner having a cur rent density of about 50 ampcres per square foot of anode surface. About from 90 to 120 ampcrcs are used per ton ore.

Example 3: .2000 pounds of the pulverized ore are suspended in a solution of 2 pounds of thiocyanate, 2 pounds caustic soda or caustic lime in an agitation tank, the mixture being in the proportion of two parts of said solution to one part of ore. This mixture of ore and solution is continuously circulated for a period of eight hours through an clectrolyzer having a current density of about 50 amperes per square foot of anode surface. About from 00 to 120 ampcres are used per ton otore.

It will be seen that the function of the electric current is simply one to produce nascent oxygen or liberate iodin from the haloid salt. The electric current in the first and second examples liberates iodid from the contained potassium iodid which coinbincs with the cyanid or the sulto-cyai'iid, to form cyanogen iodid. The cyanogen iodid as produced is an excellent. solvent for gold contained iii-refractory ores containing gold tellurid, sultids, arsenids, etc, third example, which does not contain halogen salt, the electric current generates po tassium cyanid trom sulfo-cyanido it. may be seen from the filllow ing equations the reason for using thiocyanate alone or in conjunction with the simple cyanid solution in preference to the ordinary alkaline cyanid solution is that, if cyanid solution be used without containing sulfocy-- or the addition thereof, the nascent oxygen produced by the electric current destroys the cyanid by converting the same into cyanate, which is not a gold solvent,

in the and, therefore, simply results in the destruction of the c'yan1d,after the following equation (1) KCN-t-O KCNO; whereas by using thiocyanate the equation as V t (2) KCNS+H,O-t30:KCN-t-ILSO itwill be seen from the equation X0. 2 that cyanid is produced when the solution is kept alkaline, and the cyanid so formed is not decomposed as long as there is thiocyanate present in the solution. By adding a halogen compound to the thiocyanate solution which may or may not contain free alkaline cyanid and electrolyzing same, the following equation takes place:

(a KG 'S-t-KI+&O:IGN+K SO is prevented if the solution be substantially acid, but the solution may be alkaline, neu.v

tral or slightly acid. lly slightly acid, I

mean this? that while a solution of thio-' cyanate may be technically termed slightly acid because showing acidity to certain tests, yet for practical purposes it is suhstantially non-acid. Such a solution l catt a substantially non-acid solution as well as those which are alkaline or neutral.

Having thus described my invention and examples of ditlerent ways of carrying it into effect, it will be understood that various modifications and changes in the described processes may be made and equivalent sub stances may be employed without departing from the spirit of my invention and Without exceeding the scope of my claims.

What I claim and desire to secure by Letters Patent of the United States is:

1. The process of treating ore containing precious metals which consists in subjecting ore to a thiocyanate solution, containing a halogen salt, and electrolyzing the mixture.

2. The process of treating ore containing precious metals whiclrcpnsists i'n subjecting ore to a solution containing a thiocyanate, a soluble cyanid and a halogen compound, and electrolyzing the mixture.

The process of treating ore containing precious metals which consists in subjecting the ore to a solution containing thiocyanate, and a soluble iodin compound, and electrolyzing the mixture.

4:. The process of treating ore containing precious metals which consists in subjecting ore to a solution containing a thiocyanatc, a soluble cyanid, and a soluble iodin compound, and elcctrolyzing the mixture.

The process of treating ore containing precious metals which consists in subjecting the ore to a substantially non-acid'solution of thiocyanate, and elcctrolyzing the mixture.

(3. The process of treating ore containing precious metals which consists in subjecting the ore to a substantially non-acid solution of thiocyanate containing a soluble cyanid, and electrolyzing the mixture for a sufiicicnt period to extract the precious metals.

in testimony whereof I have hereunto signed my name to this specification in the presence of two subscribing witnesses.

JOHN COLLINS CLANCY.

Witnesses M. E. McNINcI-I, A. B. Aimnns. 

